1. Field of the Invention
The present invention relates to a drawing processor which allows a machining shape to be plotted efficiently by the registration and quotation of dimensional information corresponding to machining shape information, and to a machining program processor and a machining program processing method which allow a machining program to be written efficiently using a drawing processor.
2. Description of the Background Art
FIG. 26 is an arrangement diagram illustrating a CAD/CAM apparatus known in the art, wherein the numeral 1 indicates a keyboard, 2 denotes a mouse, and 3 represents a tablet, each of which is an input device for inputting graphic data and character data. 4 designates a shape generator for converting graphic data into an internal storage format, 13 indicates internal memory for storing graphic data, 14 shows a parts library for storing a shape as a part or reading it into the internal memory 13, and 19 designates a shape analyzer. 20 denotes an NC data generator, 21 represents an NC program generated by the NC data generator 20, 22 shows a machining path display, and 23 indicates a CRT.
The operation of the CAD/CAM apparatus will now be described with reference to FIG. 26. First, graphic data is input from the input devices, such as the keyboard 1, mouse 2, and/or tablet 3. The shape generator 4 converts the graphic data into information in accordance with the internal storage format. This information is stored temporarily in the internal memory 13 for processing. When the information stored in the internal memory 13 is to be retained for long period, the information is converted into a file format as a shape part and is stored in the parts library 14. The shape part stored in the parts library 14 is may be transferred back to the internal memory 13, for example, when an NC program is to be generated. On the basis of the information stored in the internal memory 13, the shape analyzer 19 can create information that defines a machining path and is useable in the generation of an NC program. The NC data generator 20 is operative to add other NC information to the machining path information and to output an NC program 21. The machining path display 22 can convert the machining path information into graphic information and display the graphic information on the CRT 23.
In the known CAD/CAM apparatus which is arranged as described above, an operator can plot the graphics in two ways. First, the operator can plot the graphics, and thereby create graphic data, by using the input devices, such as the keyboard 1, mouse 2 and/or tablet 3. Second, the operator can plot the graphics, and thereby retrieve the graphics data, by calling desired graphics shapes that have been pre-registered in the parts library 14. When the parts library 14 storing fixed data is employed, each of the graphics (e.g., representing standard parts) must all be registered into the parts library 14, even if identical in shape but different in some or all dimensions. For this purpose, a large-capacity storage device is required for the parts library 14.
In addition, machining conditions for the generation of the NC program used to machine the selected shapes must be added and associated with each selected shape.
Another conventional apparatus replaces graphics registered into the parts library 14 by parametric diagrams, as disclosed in Japanese Patent Disclosure Publication No. 175504 of 1991. The apparatus concerned is operated as indicated by the flow chart in FIG. 27 to create an NC program from a parametric diagram registered in the parts library 14.
Namely, the operator quotes a parametric diagram registered in the parts library 14 (step 201) and inputs all specific dimensional values to the changeable dimensions in the quoted parametric diagram (step 202). The operator then indicates the shape to be machined (step 203) and sets machining conditions one by one for the shape indicated (step 204). Finally, an NC program is generated (step 205).
As is clear from FIG. 27, this conventional apparatus does not require all shapes to be registered into the parts library 14. However, it does require shape data to be input every time a graphic shape is to be defined and also requires machining conditions to be set for each defined shape, as in the background art shown in FIG. 26.
As described above, the background art requires the performance of a great many processes, in proportion to the number of shapes used, for the activity beginning with shape plotting to the output of an NC program that may be used for machining.